Symptoms: Accessing to the QNAP web administration page (http://192.168.1.102:8080) gives a blank page.
Curiously, this does not happen with IE9 or Chrome, but only with Firefox 6 and does not concern access via https.
Solution: This is related to the filtering of web pages by Eset NOD32 v5.
To fix this:
NOD32 Setup | Web access protection | Configure
Web and email | Web access protection | Protocol filtering | Excluded IP addresses
and add address 192.168.1.102
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